The invention relates to a device for supplying fresh air to the passenger space of a vehicle having a body front end preceding the passenger space in the driving direction and surrounding an engine space coverable by an engine hood, with a fresh-air inlet arranged on the top side of the body front end and with an air distributor box which is located underneath it and which is covered with an air filter towards the fresh-air inlet and is equipped with a water run-off.
In a know ventilation device of this type (German patent specification 1,188,458), the fresh-air inlet is arranged in the body front end underneath the windscreen. The air distributor box is attached by means of its inlet port to the underside of the body sheet and surrounds the fresh-air inlet by means of a gasket located on the end face. The air filter is arranged obliquely in the inlet port. Underneath the filter region located at the rear in the driving direction there is a drop-collecting strip, and in the bottom of the air distributor box there are water run-off orifices. To change the filter, the air distributor box accessible from the engine space has to be removed as a complete unit. The filter change is therefore highly time-consuming and costly, and therefore filtering is restricted to air filtering on dust filters for dirt particles which become contaminated only over a relatively long period of time and which are only slightly sensitive to water. It is not possible to use pollutant filters, for example activated-charcoal filters, which lose their chemical filtering property under wet conditions.
An object on which the invention is based is to improve a device of the type mentioned in the introduction, in such a way that, on the one hand, the filter change can be carried out easily and quickly without a stay in the workshop, and on the other hand, the air filter is protected completely from water.
In a device of the above noted type, this object is achieved by providing an arrangement wherein the fresh-air inlet is arranged in the engine hood and the water run-off is arranged on the top side of a hood like filter cover which covers the air filter facing the fresh-air inlet and is fastened releaseably to the air distributor box and carries air throughflow orifices in its casing region.
In the ventilation device according to the invention, by arranging the fresh-air inlet in the engine bonnet or hood, when this is opened the filter cover according to the invention is exposed and can be removed by hand, without a tool, from the inlet port of the air distributor box. The air filter is thereafter directly accessible and can easily be exchanged. After the filter cover has been reattached, the air filter is portected completely against water. The fresh air entering via the fresh-air inlet with the engine bonnet closed is sucked in via approximately vertically aligned air inflow orifice in the casing of the hood-shaped filter cover. Water flowing in via the fresh-air inlet is conveyed away on the top side of the filter cover. Either filters acting as a dirt filter or so-called pollutant absorption filter can be used as an air filter.
Advantageous embodiments of the ventilation device according to the invention, with expedient development and designs of the invention are illustrated and described below.
In a preferred embodiment of the invention, the so-called fresh-air flaps are assigned to the air inflow orifices in the filter cover. The advantage of this is that air passes through the air filter only when there is a fresh-air requirement, that is to say when fresh air is needed in the passenger space. The service life of the air filter is thereby increased substantially, this being of essential importance especially when pollutant absorption filters are used.
In a further feature of embodiments of the invention, the filter cover, on its top side facing the fresh-air inlet, carries a baffle web which extends round in the manner of a collar and on which is attached an annular mesh which serves as a coarse filter and is inclined towards the center and which, with its end orifice facing away from the baffle web, surrounds the fresh air inlet. The coarse filter serves for clearing particles of dirt and dust from the fresh air, so that the following air filter is subjected to less load, thus contributing to a further increase in the service life. During the filter change, the coarse filter on the removed filter cover can be cleaned in a simple way by means of compressed air.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.